Rigby, Quicksilver & Bullet Alloys

For a period during the 1870s long range target shooting captivated the public and much coverage of the sport was given by the press. Following the Centennial Rifle Match of 1876, the New York Herald devoted an article to small arms. In considering the shooting made at Creedmoor for the Centennial Trophy (now known as the Palma Trophy) on 13-14 September 1876 the following was noted with regards to bullets:

The greater number of misses at Creedmoor by the American team than that recorded against their opponents is to be accounted for easily enough. The Rigby bullet is hardened with quicksilver, the percentage of which has not been altered for years, whereas the Americans were using projectiles hardened with tin, and different percentages of that alloy were employed in different batches of the bullets, some of which were, of course, harder than others. The consequences of this inequality was that some of the softer bullets had too much “upset” and leaded the bore, while others were too hard and did not take the rifling. Notwithstanding this great drawback, which was understood by few present on the day of the match, the Americans won; and when they shall have obtained a bullet of more uniform density that that now used they will, in future contests, by further ahead of their rivals than hitherto.

New York Herald, 11 November 1876

Reference above is made to Rigby bullets hardened with quicksilver; this is a common name for the chemical element mercury. Can anyone confirm the use of quicksilver in Rigby bullets?

Some further passing reference was made to hardened bullets in use by John Rigby & Co in the New York Herald in 1880, when discussing the forthcoming Ireland vs USA long range match at Dollymount that year.

A NEW WEAPON

The Messrs. Rigby are hopeful of being able to supply the Irish Team with a new breech-loader, for which superior advantages are claimed. The new system consists of a certain combination of rifling and of the bullet. The bullets used with the new weapon are much harder than those of the Sharp or Remington rifles, and the friction between them and the barrels has been reduced to a minimum. English powder is used, and the Messrs. Rigby hope the necessity of elaborate cleaning will be obviated, while unaccountable misses are completely abolished.

New York Herald, 20 May 1880

At this time, riflemen in the US were using hard bullets; the relative hardness of the bullets may not therefore be as great as suggested by the article above. There does however appear to be a shift to hard bullets by Rigby, likely associated with the shift to breech loaders. A further description of Rigby bullets can be found in Lieut.-Colonel H. Bond’s "Treatise on Military Small Arms and Ammunition" (1884) in which he describes the bullet used in Rigby military breach loader and match rifles as:

530 grains in weight; point ogival, rather acute, and hardened by a certain process which gives them a specific gravity greater than the alloys of lead and tin in general use.

To date no specific information as to the alloy employed has been identified. Can any help?

Footnote

With reference to the above and the use of quicksilver, the late Peter Jacques (past President of the Muzzle Loaders Association of Great Britain) sent me information he found as a 'side note' within one of Alexander Henry’s (1818-1894) original shop books:

Match and military bullet formula

Lead 94lbs 5ozAntimony 3lbs 4ozMercury 2lbsBismuth 7oz

Are there any other formula known that have made use of mercury as a bullet-hardener?